ACUPUNCTURE—How It Works
Acupuncture ( Latin: “Acus punctura”, meaning “needle puncture” ). It’s use has been recorded for over 2000 years.
WHAT ARE ACUPUNCTURE POINTS?
Points where local or referred pain arises in association with certain disorders. Supposedly only millimetres in diameter, and located on the skin. It has been suggested that they appear to be the terminal nerve endings of peripheral nerves.
NEUROPHYSIOLOGY
Acupuncture is a method of manipulating synaptic mediators via the Cutaneo-Visceral Reflex (skin to organ reflex) to effect a healing process. This reflex explains why stimulating the skin at specific points has an effect on internal organs and other body areas. It is a process of neural transmission (nerve impulses). The needle, once inserted through the skin, liberates the relevant chemical mediators (neurotransmitters), which are substances released into the nervous tissue to transmit impulses from the nerve fibre to the receptor organ. They are small molecules consisting of only a few amino acid links that act rapidly across short distances from one neuron (nerve cell) to a single specific target neuron. These neurotransmitters are held in hundreds of little sacs clustered around the tip of the axon. When the neuron sends an electrical charge down the axon, the bundles of neurotransmitters are released from the vesicles, cross the synaptic gap, and interact with receptors on adjacent neurons, fitting into the receptors like a key into a lock. There. the neurotransmitters alter the cellular membrane in such a way as to generate an electric potential, which is then carried up to the cells central body, producing either a stimulating or inhibitory effect. This “chemical mediator system” is a chain of enzymatic reactions which, once triggered, very quickly generates a series of biologically active compounds that largely affect the receptors located close by the synthesis area, and are converted into less active, or inactivated metabolites. Each specific type of electrical stimulation, consisting of a unique combination of waveform, frequency, amplitude, and current, triggers the release of a specific peptide, as well as endorphins (pain killers) that can act both like neurotransmitters and hormones. The primary neurotransmitter is acetyl choline which is essential for brain function. Once released, it is hydrolized by the enzyme cholinesterase. Other principal mediators are norapinephrine and dopamine, with some others being serotonin, histamine, vasopressin, oxytocin, adrenaline, etc.
To summarize, the effects of acupuncture are produced by a) electrical mechanisms (activated by the end-plate potential) (b) chemical mechanism (determined by the chemical mediators).
Science would argue against the existence of energy channels (meridians), instead seeking to explain why acupuncture works in terms of reflexes, which may be either segmental ( “short” reflexes corresponding to the dermatomes ), or intersegmental ( “long” reflexes that don’t follow the dermatomes ). For example, acupuncture points on the torso, both anterior and posterior, are mainly segmental, and affect organs lying in close proximity. Points on the anterior aspect of the arm are also mainly segmental, however, posterior arm points are inter-segmental. Points on the head tend to affect local areas, although they don’t correlate with current medical knowledge of dermatomes. Presumably, they follow local reflex arcs similar to segmental reflexes, although distant effects do occur, especially with nose and ear points. Points on the legs are inter-segmental, and can affect areas up to ten dermatomes away, although local disease should be treated locally.
Shane Shiels
